Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)

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By Barnabybear
#44671 Hi, I also have some blue and the black like you. I did check this out, I'm sure it was a pull up resistor on REST. The early ones suffered from a resetting problem and I'm sure this was put on some boards to prevent this happening if REST was left floating.